


A Demon's Vessel

by Night_the_Dragon



Category: Final Fantasy VII, Kingdom Hearts
Genre: Alternate Universe, Eventual Smut, M/M, Mpreg, Original Character(s)
Language: English
Status: In-Progress
Published: 2017-04-04
Updated: 2017-04-08
Packaged: 2018-10-14 20:53:38
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,886
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10544174
Author URL: https://archiveofourown.org/users/Night_the_Dragon/pseuds/Night_the_Dragon
Summary: When Roxas and Sora's lives change drastically, they discover many new things about themselves. For one, they're Keyblade bearers. Second, their parents weren't who they originally thought. And third, they're each a vessel for a powerful demon. ...wait, what?!





	1. Prologue

**Author's Note:**

  * Inspired by [A Demon's Heart](https://archiveofourown.org/external_works/281808) by sadistic-neko. 



> Okay, so, I have a confession: this fic is inspired by “A Demon’s Heart” on Fanfiction.net, and since it’s unfinished, and hasn’t been updated in almost 3 years, I decided to make my own spin on it, so please don’t get mad if it seems similar, if you’ve even read that one. This is also why I’m only posting it on AO3, so I don’t suffer any backlash, since the fic isn’t on AO3. Enjoy~  
> Disclaimer: I own nothing but Night & Shadow.

It all started back when two twin boys were born to a couple. Cloud Strife and Zack Fair were beyond happy to have their sons, Sora and Roxas, when they were born, but tragedy struck the new family shortly after the twins’ birth. Two powerful demons, a fire demon and a shadow demon, lost their physical bodies and were each forced to find a vessel to inhabit and rebuild their strength. As it so happened, they found their vessels in Roxas for the fire demon, and Sora for the shadow demon. Cloud and Zack were devastated, as their sons would become magnets for the Heartless, should the dark creatures ever come to Destiny Islands.  
Vowing to protect their sons from this knowledge, the two former warriors manage to acquire the aid of the demons’ most loyal companions, Night and Shadow. Night was completely loyal to the fire demon, even in the demon’s dormancy, and ended up bonding with Roxas. Shadow, on the other hand, bonded with Sora, due to his loyalty to the shadow demon. The twin dragons protect their bonds from any harm as they grow up, preventing the demons’ power from having to be expended. After all, if the vessels perish, so too do the demons they house.  
They also keep the secret of the demons’ existence from the boys, so as to keep them safe. Sixteen long years have passed since the demons chose Roxas and Sora as their vessels, and miraculously, without incident. This is where the story begins, though. Despite the safety of Destiny Islands, everything will soon change.


	2. Chapter 1

**Summary for the Chapter:**

> All from Roxas's POV, so that should help straighten things out. Enjoy~

**Notes for the Chapter:**

> Disclaimer: I own nothing but Night and Shadow.

X*X(Roxas)X*X  
“Roxas, time to get up,” my mom, Cloud, said as he came into my room, making me grumble and curl further into a ball under my blanket. “Roxas…” he sighed.  
“Dun wanna get up…” I mumbled pitifully.  
“Come on, Rox. Zack, Sora, and Shadow are waiting for pancakes, and I didn’t want to make them until you were up,” Cloud told me, and I groaned loudly.  
“Maaaaaan… All right, I’m up…” I sighed, propping myself up on my elbow as Night yawned widely from his nest on the floor at the foot of my bed.  
“Too early…” the silver dragon muttered, stretching out in a cat-like manner and yawning again before crawling out of his nest.  
“It’s not that early, so you two had best hurry or else the pancakes will be all gone by the time you make it to the table,” Cloud warned with a chuckle, ruffling my hair lightly before leaving my room. Once the blonde was gone, I sighed, before sitting up in bed.  
“I highly doubt you want to miss out on pancakes, especially with Sora’s appetite, so let’s get down there,” Night said, shaking himself briefly to wake up further.  
“Right, just need to get dressed,” I agreed, sliding out of bed. I then changed out of my pajamas and into my usual attire before Night hopped onto my shoulder and we headed to the kitchen and dining room. There we saw Sora pouring an almost outrageous amount of syrup over his stack of four pancakes, while Zack, Sora and my dad, only had two thick ones. I knew how he liked his pancakes, though, since we both did ours the same way. Both Cloud and I would spread butter on each pancake, and then pour a little syrup on each one, too.  
“Good morning, Rox,” Zack greeted, pausing in putting a bite of pancakes in his mouth to speak.  
“Morning, Dad,” I yawned as I sat down.  
“Good morning, Roxas!” Sora grinned brightly before shoving a forkful of pancakes into his mouth.  
“Morning, Sora,” I chuckled. I watched idly as Sora’s bonded dragon, Shadow, nodded to Night in greeting as the silver dragon joined his twin brother at their spot they ate at near the table. I soon noticed the reason for the silent greeting, though: Shadow was eating half of a raw steak, while the other half was on Night’s own plate.  
“How many pancakes do you want, Roxas?” Cloud asked as he grabbed the ladle to pour pancake batter onto the griddle.  
“I’ll just have two, Mom, thanks,” I said, and he nodded.  
“Then three it is,” he smirked. Before I could protest, though, he added, “I know how you’ll want a third one after the first two. And I’m not making a single pancake after I make mine.”  
“Fine…” I sighed, but smiled anyway. Soon enough, my pancakes were ready, and Cloud set my plate in front of me. “Thanks, Mom.”  
“Of course.”  
Once I had spread butter and poured a bit of syrup on each pancake, I began to eat my breakfast. As my twin and dad ate, I noticed Cloud making a couple of lunches for himself and Zack, which meant they were working today. Oh well. Never a day off when there’s construction to be done, I guess.  
“You guys have work at the site again today, huh?” I guessed, looking at Cloud. The blonde swallowed his food before replying.  
“Yeah, but we know you boys will be okay. Just hang out at the island if you want,” he said. “We’ll be home by sundown, though.”  
“Okay, Mom,” Sora nodded, and I nodded, too. Finally, we all finished eating, and then we saw Zack and Cloud off as they left for their job. Once they were gone, Sora and I looked at each other, then our reptilian friends.  
“You guys wanna go to the island, then?” Shadow asked, and Night looked at his brother before rolling his eyes.  
“Of course they do, dumbass,” he snorted. “There’s more fun to be had over at the island.”  
“Definitely,” I agreed. “Let’s get our stuff and go.”  
“Right!” Sora nodded eagerly, and we gathered up some stuff we took with us to the island normally, before setting out for the island, Sora on Shadow’s back and me on Night’s as the two dragons flew there, having shifted to their larger sizes for the occasion as usual. Once they landed, Sora and I slid off of our partners’ backs, only for the two to suddenly bristle in alarm and fear as soon as they shifted back to their smaller sizes.  
“What’s wrong, Night?” I frowned, before he suddenly snarled, looking at Shadow.  
“They’re finally here,” he growled.  
“Yeah,” the black dragon nodded.  
“Who’s here?” Sora asked.  
“The Heartless,” the twin dragons spat in unison. The name immediately sent a chill down my spine, right before hundreds of black, shadowy creatures with glowing yellow eyes poured out of the cave where Sora and I used to draw on the rock walls. Sora and I watched, terrified, as Shadow and Night leapt into action, shooting black and silver flames at the creatures and slashing through them with their razor-sharp claws. However, a sudden surge of them from their group shot at Sora and me, making us flinch and close our eyes as we heard the panicked cries of our partners.  
…But nothing hit us. Opening my eyes, I was stunned to see two odd, key-like weapons in my hands, one being black and more slender with an almost chain-like body, and the other being white and a bit wider. I glanced at Sora and saw he only had one, but his had a silver body and end with a yellow-gold part around the handle.  
The weapons in our hands kept the Heartless back, as it seemed they were frozen by the power of the blades.  
“Keyblades?!” I heard Night and Shadow gasp, before they swiftly ran over to us, Night clinging to my shoulder and Shadow stuck to Sora’s.  
“Whatever you guys do, stay with us!” Night yelled, right before the Heartless broke free from being frozen, and slammed into us, sending us into darkness.

X*X*X*X*X*X*X  
“…Roxas? Roxas, wake up!” Night’s voice called out to me, and I groaned, before I opened my eyes to see the silver dragon sitting in my lap, watching me worriedly as Shadow tried to wake Sora nearby.  
“What…happened…?” I mumbled, rubbing the tiredness from my eyes.  
“Destiny Islands…was consumed by the darkness…” my friend sighed.  
“What?!” I gasped.  
“The Heartless took over, remember?” he reminded me softly. “Right after you two got your Keyblades, they broke free and attacked…”  
“But…what about Mom and Dad?” I asked, feeling like ice was injected into my veins at the thought of losing them to those monsters.  
“Zack and Cloud are much stronger than you know. Trust me, they’re probably somewhere either here or in another world,” Night soothed, sensing my distress. I heard Shadow starting to comfort Sora shortly after, before the brunette jumped to his feet, startling the rest of us.  
“We’re in a new world?!” he gasped with a grin.  
“You turned around quick,” Shadow huffed.  
“Aww, come on! We’re in a new world, guys! Let’s go check it out!” Sora crowed, dancing in place.  
“Easy, Sora. Don’t go running off without us,” I growled warningly.  
“Roxas! Don’t be a stick in the mud!” my twin whined.  
“And don’t you be a dumbass,” I retorted.  
“You can’t just go running off without us, Sora. What if the Heartless attack? You don’t know how to summon your Keyblade yet,” Shadow pointed out. There was that word again; Keyblade.  
“What exactly are Keyblades?” I asked Night, as Shadow kept Sora from bolting off on his own.  
“They’re powerful weapons that utilize the power of light to defeat Heartless and other such creatures. Keyblades choose their master, so not anyone can become a Keyblade wielder,” Night explained. At this, Sora finally settled down, and sat back down to listen. “The fact that the Keyblade chose both of you means you’ll be magnets for the Heartless, as the light it has attracts them, strangely enough, considering they’re creatures of darkness.”  
“How…how do we summon them?” I asked softly, noticing the weapons were nowhere to be seen.  
“I’m…not experienced with it, since Shadow and I don’t use weapons other than our claws and fangs, so we’ll have to go with a theory I’ve heard. Focus on your hearts, and think about those precious to you. That should work,” the silver dragon suggested.  
Nodding, I tried it, focusing on protecting Zack, Cloud, and Sora if they were in danger. Immediately, I felt the still-foreign weight of my Keyblades in my hands, and I looked over to see Sora’s Keyblade in his hands. For some reason, when I looked at my Keyblades, I heard the names Oblivion and Oathkeeper echo in my mind.  
“Good job,” Shadow praised us. “You’ll just need some practice to make sure you can summon them quickly, but we can work on that later. Let’s see if we can find some people for now.”  
“Sounds good,” Night agreed, and he took his usual position on my shoulder, landing neatly, while Shadow jumped onto Sora’s shoulder, and even I could sense the black dragon’s excitement. I noticed Night roll his eyes at his twin behind his back, and I chuckled softly in response. We then left the alley we had ended up in, heading towards the little plaza. There was a café to our right, and a few huge doors leading to different parts of the town we were in.  
“Maybe we should try checking out this shop, Roxas!” Sora suggested suddenly in an excited voice, and I looked at him to see him looking at the shop we were standing in front of. Huh. Hadn’t noticed that one when we came out of the alley.  
“Sure, why not? Maybe someone here can tell us if Cloud or Zack are here,” I shrugged. On the inside, I was rather hopeful of that, though. After all, despite what Night had told me, I was still worried about my parents.  
‘Keep faith, Roxas. They’re looking for both of you, too, I know it,’ Night’s voice said in my mind.  
‘Right…’ I sighed internally. Sora led the way into the shop, which appeared to be an accessories shop, based off the neon sign above it, and I followed after.  
“Hello?” the brunette called out. There were a few seconds of silence, before a gruff voice answered.  
“Hang on, I’ma comin’,” was the reply, before an older blonde man rounded the corner of the back of the shop, and came over. He had a cigarette hanging from his lips, a pair of goggles on his forehead, a white shirt, baggy blue pants with a really wide orange waistband, and a pack of cigarettes was tucked under the band of his goggles. He blinked when he saw us, seeming almost…surprised. The look quickly vanished, though, and he asked, “Your world was consumed by the Heartless, too, huh?” Suddenly, a spoon was hurled at his head from somewhere in the back, hitting its mark hard. “AH!! Son of a—!”  
“Finish that sentence, and you’ll be dodging a bullet next time,” said a smooth voice threateningly. Shortly after, a raven-haired man wearing almost all black with the exception of his torn, red cloak emerged from the back of the shop. His outfit had random straps all over it, too. His crimson eyes looked at us in interest, before he sighed. “I apologize for my husband. His empathy sometimes flees him.”  
“Th-that’s okay,” Sora stuttered, watching the new man with wide eyes.  
“My name is Vincent, and this uncouth man is Cid,” the raven told us, and we bowed respectfully.  
“I’m Roxas, and this is my twin brother, Sora,” I said.  
“And I’m Night. That’s my twin brother, Shadow, with Sora,” my partner chimed in. I noticed Vincent’s eyes flicker with interest again, and he gazed at Sora and me intently for a few minutes as Cid rubbed his head and grumbled in the background before the raven spoke.  
“You two. Roxas and Sora. You’re vessels, aren’t you?” he asked suddenly, making both Night and Shadow stiffen in alarm.  
“What? What do you mean, vessels?” Sora frowned, confused. I couldn’t blame him. I was just as confused, if not more so. Looking at Night when he stiffened, I realized he wouldn’t look at me.  
“Night? Do you know what Vincent’s talking about?” I questioned, furrowing my brows. Both dragons were silent for several minutes, before they glanced at each other and then sighed.  
“Yes, we know all too well what he means,” Shadow mumbled. “You weren’t even supposed to find out for a while yet, for your safety.”  
“Find out what?” Sora asked.  
“Perhaps you should all sit down for this, as it seems this is a serious topic,” Vincent suggested. “Come with me. There’s a room you can rest and talk in back here, and I’ll bring some tea.”  
“Thank you,” Night told Vincent, a bitter note to his voice. Eventually, once we were all settled in the back room with some tea, Cid and Vincent took a seat behind us, while the twin dragons sat by the fire, with Sora and myself watching them.  
“Where to start…?” Shadow sighed.  
“From the beginning, probably,” I replied.  
“Well, it all started when you two were born, to be completely honest,” Night said. “During that time, Shadow and I were loyal followers to two powerful demons. I followed the fire demon, while Shadow followed the shadow demon. It was during a long, harsh fight against the darkness that their bodies both perished, and they were forced to quickly seek out vessels that would allow them to regain their strength while they remained dormant.”  
“That’s when they found you two,” Shadow jumped in. “See, young children, especially infants, typically make the best vessels for rebuilding strength while remaining dormant due to how much energy children have and how quickly they grow. This, however, leads to them needing to eat more than others to compensate for the shared energy. That’s why you both always had such big appetites growing up, and never gained unhealthy weight as a result.”  
“Anyway…” Night sighed, giving his brother a pointed look. “Your parents were well aware of this situation, and got Shadow and me to help protect you so our leaders wouldn’t have to expend their precious energy to keep you safe as you got older. Besides, if they had used any of their energy protecting you, you both would have found out about being vessels much sooner.”  
“You mean like when Seifer tried to bully me until you put a stop to it?” I asked.  
“Exactly. My leader would have used his energy to incinerate that asshole, and you would have been terrified since you wouldn’t have known what was happening,” Night confirmed with a nod and soft growl.  
“So…our parents knew the whole time that we’re each a vessel for a demon?” Sora questioned.  
“Yeah, but Zack and Cloud wanted to protect you, hence why they said nothing,” Shadow nodded, pausing when he noticed both Cid and Vincent tense.  
“Your parents…are Zack and Cloud?” Cid finally asked stiffly when we all four looked at them.  
“Um…yeah, why?” I frowned.  
“God damn those two idiots!” the blonde man suddenly snarled, making us jump. Vincent’s gaze darkened, and he growled.  
“Wait, you two know Cloud and Zack?” Shadow demanded.  
“Hell, of course we do! We raised them!” Cid snapped.

**Notes for the Chapter:**

> SORRY FOR THE CLIFFY!!!


End file.
